Being heavier may mean fewer hot flashes for women over 60

The study included 52 women who experienced hot flashes and were not taking medication for those symptoms.

The women's body fat percentage, waist circumference and body mass index (BMI) were also measured, and a special skin monitor and electronic diary were used to track their hot flashes.

The result: the researchers found that higher fat levels, BMI and waist circumference were associated with fewer hot flashes. These associations were strongest among white women.

However, the reduction in hot flashes associated with higher fat levels wasn't evident in women younger than 60.

One expert who was not involved in the study said the finding did make physiologic sense.

"Being heavier means more body fat that can convert androgens into estrogens," explained Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City. That should mean that heavier, postmenopausal women will have more circulating estrogen than lean postmenopausal women, "which would explain the fewer hot flashes in the heavier postmenopausal women," he said.

The study also "provides a more nuanced understanding of the relationship between body size and hot flashes, emphasizing the important role of age," lead author Rebecca Thurston, of the University of Pittsburgh, added in a news release from the Endocrine Society.

Mezitis stressed, however, that the finding should not be seen as a "green light" for older women to pile on excess pounds.

"Being heavier means more body fat and higher insulin resistance and higher risk for metabolic syndrome," a constellation of unhealthy risk factors that can bring on heart disease, Mezitis said. "Higher estrogens may be to a certain extent cardioprotective, but I think studies will show more [arterial] risk than benefit in heavy postmenopausal women."

Another expert agreed. Dr. Stuart Weinerman, chief of the division of endocrinology at North Shore-LIJ Health System in New Hyde Park, N.Y., said that "weight has multiple health effects, and this would not be evidence of finding an ideal body weight for anyone."

The findings were released online Aug. 31 in advance of publication in the October print issue of the Journal of Clinical Endocrinology & Metabolism.